The price, therefore, of the coarse, and still more that of the precious metals, at the most fertile mines in the world, must necessarily more or less affect their price at every other in it. The price of copper in Japan must have some influence upon its price at the copper mines in Europe. The price of silver in Peru, or the quantity either of labour or of other goods which it will purchase there, must have some influence on its price, not only at the silver mines of Europe, but at those of China. After the discovery of the mines of Peru, the silver mines of Europe were, the greater part of them, abandoned. The value of silver was so much reduced, that their produce could no longer pay the expense of working them, or replace, with a profit, the food, clothes, lodging, and other necessaries which were consumed in that operation. This was the case, too, with the mines of Cuba and St. Domingo, and even with the ancient mines of Peru, after the discovery of those of Potosi. The price of every metal, at every mine, therefore, being regulated in some measure by its price at the most fertile mine in the world that is actually wrought, it can, at the greater part of mines, do very little more than pay the expense of working, and can seldom afford a very high rent to the landlord. Rent accordingly, seems at the greater part of mines to have but a small share in the price of the coarse, and a still smaller in that of the precious metals. Labour and profit make up the greater part of both. A sixth part of the gross produce may be reckoned the average rent of the tin mines of Cornwall, the most fertile that are known in the world, as we are told by the Rev. Mr Borlace, vice-warden of the stannaries. Some, he says, afford more, and some do not afford so much. A sixth part of the gross produce is the rent, too, of several very fertile lead mines in Scotland.